Correct option is D
When a dielectric material is placed in an electric field, it polarizes and resists the flow of electric current. However, if the electric field strength is increased beyond a certain critical point, the dielectric material can no longer withstand the field. At this point, the insulating properties of the dielectric break down, and it becomes conductive. This phenomenon is known as dielectric breakdown.
(a) Avalanche breakdown: This occurs in semiconductors and is a process where carriers (electrons and holes) gain enough kinetic energy from the electric field to create additional electron-hole pairs through impact ionization, leading to a sudden increase in current.
(b) Reverse breakdown: This term generally refers to the breakdown of a diode in reverse bias, where the reverse voltage exceeds a certain threshold, causing a large reverse current to flow. This is commonly associated with Zener diodes.
(c) Zener breakdown: This occurs in Zener diodes at a specific reverse voltage (Zener voltage). It involves the tunneling of electrons through the depletion region of the diode, leading to a controlled breakdown and allowing current to flow in the reverse direction.
(d) Dielectric breakdown: This occurs in insulating materials (dielectrics) when the electric field strength exceeds a critical value, causing the material to become conductive and lose its insulating properties.
the correct answer is dielectric breakdown.
